This is a question specifically for the people who have a turn-on of seeing their partner with another person. Years ago, I would have addressed this only to men, but I do know that many females get off on seeing their husband play with another lady.
I can't put a finger on exactly what drew me into this kink. I thought maybe it had something to do with me easing myself into accepting my bisexual desires, but now I realize that I had some interesting thoughts on sharing as early as Junior High school. I wrote a while back about the girl who lived on the other side of the fence from me, how I crushed on her but she was simply out of my league. We were friends and that was the extent of it. Yet I recall that I often talked to her about her boyfriend and she would offer details of their make-out sessions, complaints she had about him and his techniques. Perhaps these conversations led me down the road of compersion and ultimately, an interest in sharing someone I cared for with someone else.
I'd be interested in comments from anyone who now, as an adult has either been involved in the hotwife/swinger lifestyle, was it something they were drawn to from their youth, and if so, what you think led you down this road. If you don't want to comment, feel free to e-mail me privately.